Proposal (442) to South American Classification Committee
Recognize
Phaethornis aethopyga as a valid
species
Effect
on SACC list:
This would add a “new” species to SACC list.
Background: This is a quite simple case and there
is not much to say here that is not said in the Abstract of Piacentini et al. (2009). Zimmer (1950) described aethopyga as a new subspecies of the
(then) broadly defined Phaethornis
longuemareus group. Nobody ever studied its taxonomic status until the
1990’s, when Hinkelmann (1996) misinterpreted the plumage pattern of the 3
specimens available to him and proposed that aethopyga was a hybrid between P.
rupurumii amazonicus and P. ruber.
Given that it was treated either as a subspecies or a hybrid, it did not appear
in SACC’s main list or in the Hybrid and Dubious Taxa list.
New data: The current SACC Note reads as
follows:
9bb. Hinkelmann (1996) proposed that the
subspecies P. l. aethopyga
represented hybrids between P. ruber and P.
rupurumii amazonicus. Piacentini et
al. (2009) showed that aethopyga was
not only a valid taxon but also probably worthy of species rank.
Piacentini et al. (2009) have reanalyzed the case
based on 18 specimens of P.
“longuemareus” aethopyga [the three examined by Hinkelmann plus 15 recently
collected by us or colleagues], plus ca. 250 specimens related to the “longuemareus group” (sensu Zimmer 1950),
and 66 and 211 specimens of the two alleged parental species P. rupurumii amazonicus and P. ruber, respectively. [Here comes a
copy of the second half of the Abstract]: Despite showing some differences
related to age and sex, all specimens agree in the general plumage pattern and
are fully diagnosable when compared with any other taxon of the genus. The
hypothesis of a hybrid origin becomes unsustainable when one notes that (1) P. l. aethopyga has characters that are
unique and absent in the purported parental species, such as the white outer
margins at the base of the rectrices; and (2) P. l. aethopyga occurs far from the distribution of one of the
alleged parental species. Furthermore, field data show that P. l. aethopyga has attributes typical
of a valid and independent taxon, such as lekking behavior. Therefore, given
its overall diagnosis, P. aethopyga
could at least be treated as a phylogenetic species. Yet its morphological and
vocal distinctiveness with respect to other Phaethornis
spp. in the “Pygmornis group” is
greater than that observed between some species pairs traditionally regarded as
separate biological species within the group, which supports its recognition as
a species under the biological species concept.
I may add that,
after publication, I have studied many more specimens (including five additional
P. aethopyga) and listened to new
recordings that not only confirmed our findings, but made me sure that P. aethopyga is among one of the most
distinct species of the genus.
English name: P. aethopyga was already called Tapajós
Hermit by birdwatchers even before our (or any) analyses became available, and
indeed we suggested to keep that name since it highlights the center of
endemism to which P. aethopyga seems
restricted.
Recommendation: Of course I recommend a YES vote to
recognize it as a valid species.
Literature
cited:
Hinkelmann, C. 1996.
Evidence for natural hybridization in hermit hummingbirds (Phaethornis spp.). Bulletin of the British Ornithologists’ Club
116:5–14.
Piacentini, V. Q.,
A. Aleixo, and L. F. Silveira. 2009. Hybrid, subspecies or species? The
validity and taxonomic status of Phaethornis
longuemareus aethopyga Zimmer, 1950 (Trochilidae). Auk 126: 604-612.
Zimmer, J. T. 1950.
Studies of Peruvian Birds, no. 55. The hummingbird genera Doryfera, Glaucis, Threnetes, and Phaethornis. American Museum Novitates 1449:1–51.
Vítor de Q. Piacentini, May 2010
Comments from Stotz: “YES. This seems like a well-documented split with a number of lines of evidence. Piacentini’s paper clearly demonstrates that Hinkelmann’s treatment of this taxon as a hybrid between P. ruber and P. rupurumii is not tenable (numerous specimens from hundreds of km away from range of rupurumii, characters not intermediate, or shared with either alleged parent.) I think the argument for not treating it as a subspecies of atrimentalis is sound, especially given the recent spate of splitting in the small Phaethornis. Morphologically, this is quite distinct from the other small Phaethornis (given that they all look the same).”